'\" te
.\" This manual page is based on documentation obtained from Karl Fox.
.\" Portions Copyright (C) 2008, Sun Microsystems, Inc. All Rights Reserved
.\" The contents of this file are subject to the terms of the Common Development and Distribution License (the "License").  You may not use this file except in compliance with the License.
.\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing.  See the License for the specific language governing permissions and limitations under the License.
.\" When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE.  If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
.TH CHAT 8 "August 29, 2021"
.SH NAME
chat \- automated conversational exchange tool
.SH SYNOPSIS
.nf
\fBchat\fR [\fIoptions\fR] \fIscript\fR
.fi

.SH DESCRIPTION
The \fBchat\fR program implements a conversational text-based exchange between
the computer and any serial device, including (but not limited to) a modem, an
ISDN TA, and the remote peer itself, establishing a connection between the
Point-To-Point Protocol daemon (\fBpppd\fR) and the remote \fBpppd\fR process.
.SH OPTIONS
The  \fBchat\fR command supports the following options:
.sp
.ne 2
.na
\fB\fB-f\fR \fI<chat file>\fR\fR
.ad
.RS 23n
Read the \fBchat\fR script from the  \fBchat\fR file. This option is mutually
exclusive with the  \fBchat\fR script parameters. You must have \fBread\fR
access to use the file. Multiple lines are permitted in the file. Use the space
or horizontal tab characters to separate the strings.
.RE

.sp
.ne 2
.na
\fB\fB-t\fR \fB\fI<timeout>\fR\fR \fR
.ad
.RS 23n
Set the timeout for the expected string to be received. If the string is not
received within the time limit, the reply string is not sent. If specified,
a 'subexpect' (alternate reply) string can be sent. Otherwise, if no alternate
reply strings remain, the \fBchat\fR script fails. A failed script will cause
the  \fBchat\fR program to terminate with a non-zero error code.
.RE

.sp
.ne 2
.na
\fB\fB-r\fR \fB\fI<report file> \fR\fR \fR
.ad
.RS 23n
Set the file for output of the report strings. If you use the keyword
\fBREPORT\fR, the resulting strings are written to this file. If  the \fB-r\fR
option is not used and you use the \fBREPORT\fR keyword, the  \fBstderr\fR file
is used for the report strings.
.RE

.sp
.ne 2
.na
\fB\fB-e\fR \fR
.ad
.RS 23n
Start with the echo option turned on. You turn echo on or off at specific
points in the \fBchat\fR script using the \fBECHO\fR keyword. When echoing is
enabled, all output from the modem is echoed to \fBstderr\fR.
.RE

.sp
.ne 2
.na
\fB\fB-E\fR \fR
.ad
.RS 23n
Enables environment variable substitution within \fBchat\fR scripts using the
standard \fI$xxx\fR syntax.
.RE

.sp
.ne 2
.na
\fB\fB-v\fR \fR
.ad
.RS 23n
Request that the \fBchat\fR script execute in a verbose mode. The  \fBchat\fR
program logs the execution state of the \fBchat\fR script as well as all text
received from the modem and output strings sent to the modem. The default is to
log through \fBsyslog\fR(3C) with facility \fBlocal\fR2; the logging method is
alterable using the \fB-S\fR and \fB-s\fR options.
.RE

.sp
.ne 2
.na
\fB\fB-V\fR \fR
.ad
.RS 23n
Request that the  \fBchat\fR script be executed in a \fBstderr\fR verbose mode.
The \fBchat\fR program logs all text received from the modem and output strings
sent to the modem to \fBstderr\fR. \fBstderr\fR is usually the local console at
the station running the  \fBchat\fR or \fBpppd\fR program.
.RE

.sp
.ne 2
.na
\fB\fB-s\fR\fR
.ad
.RS 23n
Use \fBstderr\fR.  Log messages from \fB-v\fR and error messages are sent to
\fBstderr\fR.
.RE

.sp
.ne 2
.na
\fB\fB-S\fR\fR
.ad
.RS 23n
Do not use syslog.  By default, error messages are set to syslog. This option
prevents log messages from \fB-v\fR and error messages from being sent to
syslog.
.RE

.sp
.ne 2
.na
\fB\fB-T\fR \fB\fI<phone number>\fR\fR\fR
.ad
.RS 23n
Pass in an arbitrary string (usually a telephone number) that will be
substituted for the \fB\eT\fR substitution metacharacter in a send string.
.RE

.sp
.ne 2
.na
\fB\fB-U\fR \fB\fI<phone number 2>\fR\fR\fR
.ad
.RS 23n
Pass in a second string (usually a telephone number) that will be substituted
for the \fB\eU\fR substitution metacharacter in a send string. This is useful
when dialing an ISDN terminal adapter that requires two numbers.
.RE

.sp
.ne 2
.na
\fB\fBscript\fR \fR
.ad
.RS 23n
If the script is not specified in a file with the \fB-f\fR option, the script
is included as parameters to the \fBchat\fR program.
.RE

.SH EXTENDED DESCRIPTION
.SS "Chat Script"
The \fBchat\fR script defines communications. A script consists of one or more
"expect-send" pairs of strings separated by spaces, with an optional
"subexpect-subsend" string pair, separated by a dash (as in the following
example:)
.sp
.LP
ogin:-BREAK-ogin: ppp ssword: hello2u2
.sp
.LP
The example indicates that the \fBchat\fR program should expect the string
"ogin:". If it fails to receive a login prompt within the time interval
allotted, it sends a break sequence to the remote and then expects the string
"ogin:". If the first "ogin:" is received, the break sequence is not generated.
.sp
.LP
Upon receiving the login prompt, the  \fBchat\fR program sends the string "ppp"
and then expects the prompt "ssword:". When the password prompt is received, it
sends the password hello2u2.
.sp
.LP
A carriage return is normally sent following the reply string. It is not
expected in the "expect" string unless it is specifically requested by using
the \fB\er\fR character sequence.
.sp
.LP
The expect sequence should contain only what is needed to identify the received
data. Because it's stored on a disk file, it should not contain variable
information. Generally it is not acceptable to look for time strings, network
identification strings, or other variable pieces of data as an expect string.
.sp
.LP
To correct for characters that are corrupted during the initial sequence, look
for the string "ogin:" rather than "login:". The leading "l" character may be
received in error, creating problems in finding the string. For this reason,
scripts look for "ogin:" rather than "login:" and "ssword:" rather than
"password:".
.sp
.LP
An example of a simple script follows:
.sp
.in +2
.nf
ogin: ppp ssword: hello2u2
.fi
.in -2

.sp
.LP
The example can be interpreted as: expect ogin:, send ppp, expect ...ssword:,
send hello2u2.
.sp
.LP
When login to a remote peer is necessary, simple scripts are rare. At minimum,
you should include sub-expect sequences in case the original string is not
received. For example, consider the following script:
.sp
.in +2
.nf
ogin:--ogin: ppp ssword: hello2u2
.fi
.in -2

.sp
.LP
This script is more effective than the simple one used earlier. The string
looks for the same login prompt; however, if one is not received, a single
return sequence is sent and then the script looks for login: again. If line
noise obscures the first login prompt, send the empty line to generate a login
prompt again.
.SS "Comments"
Comments can be embedded in the \fBchat\fR script. Comment lines are ignored by
the chat program. A comment starts with the hash ("#") character in column one.
If a \fB#\fR character is expected as the first character of the expect
sequence, quote the expect string. If you want to wait for a prompt that starts
with a \fB#\fR character, write something like this:
.sp
.in +2
.nf
# Now wait for the prompt and send logout string
\&'# ' logout
.fi
.in -2

.SS "Sending Data From A File"
If the string to send begins with an at sign ("@"), the remainder of the string
is interpreted as the name of the file that contains the string. If the last
character of the data read is a newline, it is removed. The file can be a named
pipe (or fifo) instead of a regular file. This enables \fBchat\fR to
communicate with another program, for example, a program to prompt the user and
receive a password typed in.
.SS "Abort "
Many modems report the status of a call as a string. These status strings are
often "CONNECTED" or "NO CARRIER" or "BUSY." If the modem fails to connect to
the remote, you can terminate the script. Abort strings may be specified in the
script using the ABORT sequence. For example:
.sp
.in +2
.nf
ABORT BUSY ABORT 'NO CARRIER' '' ATZ OK ATDT5551212 CONNECT
.fi
.in -2

.sp
.LP
This sequence expects nothing and sends the string ATZ. The expected response
is the string OK. When OK is received, the string ATDT5551212 dials the
telephone. The expected string is CONNECT. If CONNECT is received, the
remainder of the script is executed. When the modem finds a busy telephone, it
sends the string BUSY, causing the string to match the abort character
sequence. The script fails because it found a match to the abort string. If the
NO CARRIER string is received, it aborts for the same reason.
.SS "Clr_Abort "
The CLR_ABORT sequence clears previously set ABORT strings. ABORT strings are
kept in an array of a pre-determined size; CLR_ABORT reclaims the space for
cleared entries, enabling new strings to use that space.
.SS "Say "
The SAY string enables the script to send strings to a user at a terminal via
standard error. If \fBchat\fR is being run by \fBpppd\fR and \fBpppd\fR is
running as a daemon (detached from its controlling terminal), standard error is
normally redirected to the \fB/etc/ppp/connect-errors\fR file.
.sp
.LP
SAY strings must be enclosed in single or double quotes. If carriage return and
line feed are required for the output, you must explicitly add them to your
string.
.sp
.LP
The SAY string can provide progress messages to users even with "ECHO OFF." For
example, add a line similar to the following to the script:
.sp
.in +2
.nf
ABORT BUSY
ECHO OFF
SAY "Dialing your ISP...\en"
\&'' ATDT5551212
TIMEOUT 120
SAY "Waiting up to 2 minutes for connection ..."
CONNECT ''
SAY "Connected, now logging in ...\en"
ogin: account
ssword: pass
$ \ec
SAY "Logged in OK ... \en"
.fi
.in -2

.sp
.LP
This sequence hides script detail while presenting the SAY string to the user.
In this case, you will see:
.sp
.in +2
.nf
Dialing your ISP...
Waiting up to 2 minutes for connection...Connected, now logging in...
Logged in OK ...
.fi
.in -2

.SS "Report"
REPORT is similar to the ABORT string. With REPORT, however, strings and all
characters to the next control character (such as a carriage return), are
written to the report file.
.sp
.LP
REPORT strings can be used to isolate a modem's transmission rate from its
CONNECT string and return the value to the \fBchat\fR user. Analysis of the
REPORT string logic occurs in conjunction with other string processing, such as
looking for the expect string. It's possible to use the same string for a
REPORT and ABORT sequence, but probably not useful.
.sp
.LP
Report strings may be specified in the script using the REPORT sequence. For
example:
.sp
.in +2
.nf
REPORT CONNECT
ABORT BUSY
ATDT5551212 CONNECT
ogin: account
.fi
.in -2

.sp
.LP
The above sequence expects nothing, then sends the string ATDT5551212 to dial
the telephone. The expected string is CONNECT. If CONNECT is received, the
remainder of the script is executed. In addition, the program writes the string
CONNECT to the report file (specified by \fB-r\fR) in addition to any
characters that follow.
.SS "Clr_Report"
CLR_REPORT clears previously set REPORT strings. REPORT strings are kept in an
array of a pre-determined size; CLR_REPORT reclaims the space for cleared
entries so that new strings can use that space.
.SS "Echo"
ECHO determines if modem output is echoed to \fBstderr\fR. This option may be
set with the \fB-e\fR option, but can also be controlled by the ECHO keyword.
The "expect-send" pair  ECHO ON enables echoing, and ECHO OFF disables it. With
ECHO, you can select which parts of the conversation should be visible. In the
following script:
.sp
.in +2
.nf
ABORT   'BUSY'
ABORT   'NO CARRIER'
""    AT&F
OK\er\en  ATD1234567
\er\en    \ec
ECHO    ON
CONNECT \ec
ogin:   account
.fi
.in -2

.sp
.LP
All output resulting from modem configuration and dialing is not visible, but
output is echoed beginning with the CONNECT (or BUSY) message.
.SS "Hangup"
The HANGUP option determines if a modem hangup is considered as an error.
HANGUP is useful for dialing systems that hang up and call your system back.
HANGUP can be ON or OFF. When HANGUP is set to OFF and the modem hangs up (for
example, following the first stage of logging in to a callback system),
\fBchat\fR continues running the script (for example, waiting for the incoming
call and second stage login prompt). When the incoming call is connected, use
the HANGUP ON string to reinstall normal hang up signal behavior. An example of
a simple script follows:
.sp
.in +2
.nf
ABORT   'BUSY'
 ""  AT&F
 OK\er\en  ATD1234567
 \er\en    \ec
 CONNECT \ec
 'Callback login:' call_back_ID
 HANGUP OFF
 ABORT "Bad Login"
 'Callback Password:' Call_back_password
 TIMEOUT 120
 CONNECT \ec
 HANGUP ON
 ABORT "NO CARRIER"
 ogin:--BREAK--ogin: real_account
.fi
.in -2

.SS "Timeout"
The initial timeout value is 45 seconds. Use the \fB-t\fR parameter to change
the initial timeout value.
.sp
.LP
To change the timeout value for the next expect string, the following example
can be used:
.sp
.in +2
.nf
\&''"AT&F
 OK ATDT5551212
 CONNECT \ec
 TIMEOUT 10
 ogin:--ogin: username
 TIMEOUT 5
 assword: hello2u2
.fi
.in -2

.sp
.LP
The example changes the timeout to ten seconds when it expects the login:
prompt. The timeout is changed to five seconds when it looks for the password
prompt.
.sp
.LP
Once changed, the timeout value remains in effect until it is changed again.
.SS " EOT"
The EOT special reply string instructs the \fBchat\fR program to send an EOT
character to the remote. This is equivalent to using ^D\ec as the reply string.
The EOT string normally indicates the end-of-file character sequence. A return
character is not sent following the EOT. The EOT sequence can embedded into the
send string using the sequence ^D.
.SS " BREAK"
The BREAK special reply string sends a break condition. The break is a special
transmitter signal. Many UNIX systems handle break by cycling through available
bit rates, and sending break is often needed when the remote system does not
support autobaud. BREAK is equivalent to using \eK\ec as the reply string.
You embed the break sequence into the send string using the \eK sequence.
.SS "Escape Sequences"
Expect and reply strings can contain escape sequences. Reply strings accept all
escape sequences, while expect strings accept most sequences. A list of escape
sequences is presented below. Sequences that are not accepted by expect strings
are indicated.
.sp
.ne 2
.na
\fB\fB\&''\fR \fR
.ad
.RS 10n
Expects or sends a null string. If you send a null string, \fBchat\fR sends
the return character.  If you expect a null string, \fBchat\fR proceeds to the
reply string without waiting.  This sequence can be a pair of apostrophes or
quote mark characters.
.RE

.sp
.ne 2
.na
\fB\fB\eb\fR \fR
.ad
.RS 10n
Represents a backspace character.
.RE

.sp
.ne 2
.na
\fB\fB\ec\fR \fR
.ad
.RS 10n
Suppresses the newline at the end of the reply string. This is the only method
to send a string without a trailing return character. This sequence must be at
the end of the send string. For example, the sequence hello\ec will simply send
the characters h, e, l, l, o. (Not valid  in expect.)
.RE

.sp
.ne 2
.na
\fB\fB\ed\fR \fR
.ad
.RS 10n
Delay for one second. The program uses \fBsleep\fR(1) which delays to a maximum
of one second.  (Not valid  in expect.)
.RE

.sp
.ne 2
.na
\fB\fB\eK\fR \fR
.ad
.RS 10n
Insert a BREAK.  (Not valid  in expect.)
.RE

.sp
.ne 2
.na
\fB\fB\en\fR \fR
.ad
.RS 10n
Send a newline or linefeed character.
.RE

.sp
.ne 2
.na
\fB\fB\eN\fR \fR
.ad
.RS 10n
Send a null character. The same sequence may be represented by \e0.  (Not valid
in expect.)
.RE

.sp
.ne 2
.na
\fB\fB\ep\fR \fR
.ad
.RS 10n
Pause for 1/10th of a second.  (Not valid  in expect.)
.RE

.sp
.ne 2
.na
\fB\fB\eq\fR \fR
.ad
.RS 10n
Suppress writing the string to syslog.  The string ?????? is written to the log
in its place. (Not valid  in expect.)
.RE

.sp
.ne 2
.na
\fB\fB\er\fR \fR
.ad
.RS 10n
Send or expect a carriage return.
.RE

.sp
.ne 2
.na
\fB\fB\es\fR \fR
.ad
.RS 10n
Represents a space character in the string. Can be used when it is not
desirable to quote the strings which contains spaces. The sequence 'HI\ TIM'
and HI\esTIM are the same.
.RE

.sp
.ne 2
.na
\fB\fB\et\fR \fR
.ad
.RS 10n
Send or expect a tab character.
.RE

.sp
.ne 2
.na
\fB\fB\eT\fR \fR
.ad
.RS 10n
Send the phone number string as specified with the \fB-T\fR option.  (Not valid
in expect.)
.RE

.sp
.ne 2
.na
\fB\fB\eU\fR \fR
.ad
.RS 10n
Send the phone number 2 string as specified with the \fB-U\fR option. (Not
valid  in expect.)
.RE

.sp
.ne 2
.na
\fB\fB\e\e\fR \fR
.ad
.RS 10n
Send or expect a backslash character.
.RE

.sp
.ne 2
.na
\fB\fB\eddd\fR \fR
.ad
.RS 10n
Collapse the octal digits (ddd) into a single ASCII character and send that
character. (\e000 is not valid in an expect string.)
.RE

.sp
.ne 2
.na
\fB\fB^C\fR \fR
.ad
.RS 10n
Substitute the sequence with the control character represented by C. For
example, the character DC1 (17) is shown as ^Q. (Some characters are not valid
in expect.)
.RE

.SH ENVIRONMENT VARIABLES
Environment variables are available within \fBchat\fR scripts if the \fB-E\fR
option is specified on the command line. The metacharacter \fB$\fR introduces
the name of the environment variable to substitute. If the substitution fails
because the requested environment variable is not set, nothing is replaced for
the variable.
.SH EXIT STATUS
The \fBchat\fR program terminates with the following completion codes:
.sp
.ne 2
.na
\fB\fB0\fR \fR
.ad
.RS 10n
Normal program termination. Indicates that the script was executed without
error to normal conclusion.
.RE

.sp
.ne 2
.na
\fB\fB1\fR \fR
.ad
.RS 10n
One or more of the parameters are invalid or an expect string was too large for
the internal buffers. Indicates that the program was not properly executed.
.RE

.sp
.ne 2
.na
\fB\fB2\fR \fR
.ad
.RS 10n
An error occurred during the execution of the program. This may be due to a
read or write operation failing or \fBchat\fR receiving a signal such as
SIGINT.
.RE

.sp
.ne 2
.na
\fB\fB3\fR \fR
.ad
.RS 10n
A timeout event occurred when there was an expect string without having a
"-subsend" string. This indicates that you may not have programmed the script
correctly for the condition or that an unexpected event occurred and the
expected string could not be found.
.RE

.sp
.ne 2
.na
\fB\fB4\fR \fR
.ad
.RS 10n
The first string marked as an ABORT condition occurred.
.RE

.sp
.ne 2
.na
\fB\fB5\fR \fR
.ad
.RS 10n
The second string marked as an ABORT condition occurred.
.RE

.sp
.ne 2
.na
\fB\fB6\fR \fR
.ad
.RS 10n
The third string marked as an ABORT  condition occurred.
.RE

.sp
.ne 2
.na
\fB\fB7\fR \fR
.ad
.RS 10n
The fourth string marked as an ABORT condition occurred.
.RE

.sp
.ne 2
.na
\fB\fB\&...\fR \fR
.ad
.RS 10n
The other termination codes are also strings marked as an ABORT condition.
.RE

.sp
.LP
To determine which event terminated the script, use the termination code. It is
possible to decide if the string "BUSY" was received from the modem versus "NO
DIALTONE." While the first event may be retried, the second probably will not
succeed during a retry.
.SH ATTRIBUTES
See \fBattributes\fR(7)  for descriptions of the following attributes:
.sp

.sp
.TS
box;
c | c
l | l .
ATTRIBUTE TYPE	ATTRIBUTE VALUE
_
Interface Stability	Evolving
.TE

.SH SEE ALSO
.BR sleep (1),
.BR uucp (1C),
.BR syslog (3C),
.BR attributes (7),
.BR pppd (8),
.BR uucico (8)
.sp
.LP
Additional information on \fBchat\fR scripts are available with UUCP
documentation. The  \fBchat\fR script format was taken from scripts used by the
\fBuucico\fR program.
